it's been是什么时态,

it's been是什么时态, It's been snowing是什么时态 it's been a good week.是什么时态? It's been in use.这是什么时态,如何理解它的用法? it's been six years这句话什么时态 been 的作用与时态 it‘s been done这句话是什么时态?我个人觉得不是过去式加被动不是应该 it was been done吗?为什么is 是原级? it's +一段时间+since 是什么时态 have+been是什么时态 I wonder if it's because I haven't been able to be outdoors for so longI haven't been 是什么时态 现在完成时被动语态吗? It's already been written.The report has been written.这两句怎么翻译?这是什么时态?怎么有两个现在分词?帮个忙, 英语语法 he has been tested 能否缩写成 he's been tested 如果不能 he's been tested是什么时态 have been working 是什么时态 have been to是什么时态? had been doing 是什么时态? i've been ...是什么时态? had been doing是什么时态 having been done是什么时态? had been doing是什么时态